By Antonio Manaytay
Plastic is everywhere. It even finds its way in human tissues, a group of scientists reported.
“You can find plastic contaminating the environment,” says Dr. Charles Rolsky in a press conference held Monday.
It does not stop there.
Evidence has shown, according to Rolsky, “plastic is making its way into our bodies.”
Small plastic particles
Rolsky and his colleagues have found micro-plastic and nano-plastic in human tissues.
Scientists define microplastics as plastic fragments less than 5 mm, or about 0.2 inches, in diameter. Nanoplastics are even smaller, with diameters less than 0.050 mm.
Research in wildlife and animal models has linked exposure to these small plastic particles to infertility, inflammation and cancer.
Health outcomes in people are still unknown, though.
Previous studies have shown that plastics can pass through the human gastrointestinal tract.
But Rolsky and Varun Kelkar are studying if the tiny particles accumulate in human organs and how to detect them. Rolsky is a postdoctoral scholar and Kelkar is a graduate student in the lab of Rolf Halden, Ph.D., at Arizona State University.
The researchers collaborated with Diego Mastroeni, Ph.D., to get samples from a large repository of brain and body tissues.
They took samples from lungs, liver, adipose tissue, spleen and kidneys. These organs are prone to get exposure by filtering or collecting plastic monomers and microplastics.
To develop a method and test it, the team spiked nano-plastic and microplastic beads into this sample set. They analyzed the sample with flow cytometry.
This procedure has enabled the researchers to detect the beads they introduced into these samples.
The researchers also created a computer program capable of converting information on plastic particle count into units of mass and surface area.
The flow cytometry method allowed the researchers to show that they can detect nano/microplastics from tissues to which they had added.
The researchers also showed the use of μ-Raman spectrometry to study environmental contamination with microplastics, including polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene (PE).
Next, the researchers used another method called mass spectrometry to analyze 47 human liver and fat tissue samples.
The researchers did not spike the materials into these samples.
After analyzing the results, the team found plastic contamination in the form of monomers, or plastic building blocks, in every sample. Bisphenol A (BPA), still used in many food containers despite health concerns, was found in all 47 human samples.
The study is the first to examine monomer, nano- and microplastic occurrence in human organs from individuals with a known history of environmental exposure.
“The tissue donors provided detailed information on their lifestyle, diet and occupational exposures,” Halden says.
“Because these donors have such well-defined histories, our study provides the first clues on potential micro- and nanoplastic exposure sources and routes.”
“We never want to be alarmist, but it is concerning that these non-biodegradable materials that are present everywhere can enter and accumulate in human tissues,” says Kelkar.
“We don’t know the possible health effects,” adds Kelkar.
They need to to conduct epidemiological studies to determine the effects of these small plastic particles to human health.
“That way, we can start to understand the potential health risks, if any,” he says.
The researchers presented their findings at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting Monday through Thursday.